docs: repoint the preamble at COMPLETED.md where the retired sections used to be

docs/PLAN.md

@@ -6,8 +6,9 @@ dispatched against directly — **plus Phase Γ**, which did not come from those
 (it came from a direct interview, 2026-08-01) and is scoped in
 `docs/product/instrument-control-surface.md`, **and Phase Ψ**, which likewise did not
 come from the seventeen: it came from a direct list of seven defects and refinements
-(Daniel, 2026-08-01) and is specified inline in its own section below — there is no
-backing product doc for it, **and Phase Ε**, which likewise did not come from the
+(Daniel, 2026-08-01); it has landed, and now that its section here is retired, the list
+is carried verbatim in `docs/COMPLETED.md` — there is no backing product doc for it,
+**and Phase Ε**, which likewise did not come from the
 seventeen: it came from a direct request (Daniel, 2026-08-02) and is scoped in
 `docs/product/bank-package.md`, **and Phase Ρ**, likewise a direct request (Daniel,
 2026-08-02), scoped in `docs/product/render-in-place.md`, **and Phase Λ** — the Linux port
@@ -77,8 +78,9 @@ the stage lengths to 10s"* — the ceiling moves in Γ-W1-T1. **Γ-F7** (the VST
 RULED**, same day (Daniel, 2026-08-02): **Ε-F1** container format — *"proprietary
 container"*, the hand-rolled `RSBK`; **Ε-F2** import target — *"always lands as a new bank,
 with an auto suffix if name collision"*; **Ε-F3** import under a degraded tracking ledger —
-*"refuse mismatched import."* The rulings are folded into the tracks below and indexed at
-`docs/product/bank-package.md` §"Rulings". **Two of the three landed somewhere other than
+*"refuse mismatched import."* Ε-W1 through Ε-W3 have landed; see `docs/COMPLETED.md` for
+the full narrative, and the rulings remain indexed at `docs/product/bank-package.md`
+§"Rulings". **Two of the three landed somewhere other than
 the framing recommendation:** Ε-F2 dropped the proposed rename prompt in favour of a
 deterministic suffix, and Ε-F3 reversed allow-with-confirm to refuse — carried by the
 framing's own counter-argument, that the accepted tracking residual contemplates *one*
@@ -126,7 +128,7 @@ carries them as a table. What they gate is narrow and is not a matter of judgeme
   different kind of unknown, and the reason Λ-W3 exists.
 
 **Λ's six [Daniel] rulings of 2026-08-02 are settled** and are recorded in the phase section
-below in the same shape as Γ's and Ε's: the instrument is in scope; SWELL is reached by
+below in the same shape as Γ's: the instrument is in scope; SWELL is reached by
 `dlopen`ing REAPER's own `libSwell.so` rather than vendoring it; the editor is REAPER-only
 but every other host must degrade safely; macOS is out; the Linux artifact is shipped rather
 than developer-only; and a hard `unlink` prune is acceptable with a platform-aware
@@ -189,11 +191,9 @@ in Γ-W4-T1 and changes no wave boundary.
 
 ## Phase-wide acceptance criteria
 
-These bind every track in all four phases and are stated once here rather than repeated
-per track. **Phase Γ adds a set of its own**, stated in its phase header. **Phase Ψ adds
-none** — the structural heuristics, performance guardrails, and product invariants below
-bind it exactly as written (its phase header states its performance posture against the
-named hot paths).
+These bind every track in both phases and are stated once here rather than repeated
+per track. **Phase Γ adds a set of its own**, stated in its phase header. **Phase Λ adds
+a set of its own**, stated in its phase header.
 
 ### Structural (root `CLAUDE.md`, Daniel 2026-07-28)